Tuning Forks and Tests

The three tuning forks generally used include : 256 Hz, 512 Hz, 1024 Hz. Most common being 512Hz. 512 because It has appropriate decay time, Less overtones and lies in speech frequency. Compressing the prongs with fingers produces around 70 dB sound and hitting against Knee or elbow 90dB. A prediction of air-bone gap can be made if tuning forks of 256, 512 and 1024 Hz are used. • Rinne test equal or negative for 256 Hz but positive for 512 Hz indicates air-bone gap of 20-30 dB. • Rinne test negative for 256 and 512 Hz but positive for 1024 Hz indicates air-bone gap of 30-45 dB. • Rinne negative for all three tuning forks, indicates air-bone gap of 45-60 dB . Remember that a negative Rinne for 256, 512 and 1024 Hz indicates a minimum AB gap of 15, 30, 45 dB respectively.